THE DEEP SEA AND ITS CONTENTS. 319 



collected in regard to the Physics of the Ocean, affords a body 

 of data for scientific discussion of which, when it shall have been 

 fully published, advantage will doubtless be eagerly taken by the 

 various inquirers into the different branches of this subject who 

 are at present anxiously waiting for it. And, in like manner, the 

 enormous collection of marine animals that has been most carefully 

 made along the whole of the Challenger's course, and at various 

 depths from the surface down to more than four miles — the 

 locality and depth from which every specimen was obtained 

 having been accurately recorded — attests the entire success of the 

 Biological portion of the Challenger's work. But here, again, 

 however great the amount of work done, much more remains to 

 do, in the " working up " of this most valuable material. It has 

 been distributed among Naturalists of the highest competence in 

 their respective departments, each of whom will report separately 

 upon his own subject. And only when all these separate reports 

 shall have been published, which cannot be for some years, will it 

 be possible to give a general resume of the zoological results of the 

 expedition. But in the study of the bottom-deposits more progress 

 has been made ; and Mr. Murray — one of the Challenger scientific 

 staff, who was specially charged with this department during the 

 voyage — has already arrived at some results of such remarkable 

 interest as fully to justify the belief I had expressed to Mr. 

 Goschen, " that the key to the interpretation of much of the past 

 " history of our globe is at present lying at the bottom of the sea, 

 "waiting only to be brought up." 



I have been so often asked, " What has the Challenger expedi- 

 " tion done for science ? " that, notwithstanding what I have shown 

 to be the impossibility of at present giving more than a very 

 inadequate idea of the results of its work, I shall now endeavour 

 briefly to show what light these results have thrown on a few 

 general questions oi %xtdX interest; some of which were first opened 

 up in our previous deep-sea explorations, while on others not 

 apparently related to it the Challenger researches have been found 

 to cast an unexpected light. 



The question which naturally takes the first place in order is 

 that of the depth and configuration of the Ocean basins, as to which 

 little had been previously learned with certainty, except in the 



